Attachment for drill press



Nov. 16, 1965 L. P. CONOVER 3,217,555

ATTACHMENT FOR DRILL PRESS Filed Oct. 15, 1965 INVENTOR. ZUEEN P.CUNOVEIQ A TTOE/V'EY United States Patent 3,217,556 ATTACHMENT F R DRILLPRESS Loren P. Conover, Glendora, Calif, assignor of forty-five percentto Rene Pfister, Monterey Park, Calif.

Filed Oct. 15, 1963, Ser. No. 316,277 6 Claims. (Cl. 74-421) Thisinvention relates to an attachment that converts a drill press of onemaximum size to one for drilling holes of a larger size than thecapacity of the original press. This invention is an improvement of theimprovements disclosed in my Patent No. 2,784,614, issued May 12, 1957.

An object of the present invention is to provide a simplified and lesscostly structure that effects an efficient transfer of power from theinput to the torque-applying spindle by means of a simplified andpowerful speed reducer.

Another object of the invention is to provide an attachment ascharacterized that has a trimmer, less bulky shape, giving improvedvisibility of the work and, there fore, more efiicient operation.

A further object of the invention is to provide a drill press attachmentthat incorporates features of safety to insure against unduly stressingthe reducing gears of the attachment.

A still further object of the invention is to provide an attachment asabove that is sealed against leakage of lubricant housed in the body ofthe same.

'1 This invention also has for its objects to provide such means thatare positive in operation, convenient in use, easily installed in aworking position and easily disconnectedtherefrom, economical ofmanufacture, relatively simple, and of general superiority andserviceability.

1 The invention also comprises novel detail-s of construction and novelcombinations and arrangements of parts, which will more fully appear inthe course of the following description and which is based on theaccompanying drawing. However, said drawing merely shows, and thefollowing description merely describes, one embodiment of the presentinvention, which is given by way of illustration or example only.

In the drawing, like reference characters designate similar parts in theseveral views.

FIG. 1 is a side elevational view of an attachment according to thepresent invention.

FIG. 2 is an enlarged vertical sectional view thereof.

FIG. 3 is a plan view, to a scale between that of FIG. 1 and FIG. 2,showing the present attachment in operative position relative to thecolumn of a drill press.

The present attachment 5 is shown in operative relation to a drill presscolumn 6 and is held non-rotationally by an arm 7 that extends from theattachment, a lengthadjustable sleeve 8 on said arm and a coil springaround the column 6 and connected by its ends 9 to said sleeve. It isunderstood that the attachment is mounted on the axis of the drill pressdrive shaft or arbor, and that the above-described means holds steadythe attachment 5 during drive thereof by the press arbor.

The attachment 5 comprises, generally, a housing 10, an input shaft orshank 11 extending into the housing from above, the same being adaptedfor separable connection to the mentioned press arbor to be rotatedthereby, an output shaft 12 axially aligned with the shank 11, a singletaper roller bearing 13 interengaging the adjacent ends of said shank 11and shaft 12, a countershaft 14 in the housing parallel to the shaft 12,a first stage reducing gearing 15 between the shank 11 and saidcountershaft, a second stage reducing gearing 16 between saidcountershaft and the shaft 12, shear means 17 connecting the shaft 12and said reducing gearing 16 to shear in the ice event of excessivetorque resistance on the shaft 12, and leakage sealing means 18.

The housing 10 comprises a body 20 that has a through bore 21, and aparallel, smaller bore 22, said bores being in communication at 23 atthe lower portion of the body. A cap plate 24 closes the top of the bodyand has a bore 25 that is an axial extension of bore 21 and acommunicating bore coaxial with the bore 22 of the body. A bottom plate26 closes the bottom of the body. In this form of the invention, thebody 20 has flattened sides, as seen in FIG. 3, the bore 21 forming sidewalls 27. Vertically elongated openings 28 are formed in said walls, asbest seen in FIG. I. The body is formed with a laterally extendingportion 29 in which is shown a tapped seat 30 for an end of the arm 7.

The input shank 11 is provided with an upper end 31 that is adapted forseparable connection to a press arbor to be rotationally driven thereby.Said shank extends through an opening 32 in the cap plate and through aradial bearing 33 in the bore 25 of said cap plate. Integrally formed onthe shank 11 is a spur pinion 34 in the bore 25 beneath the bearing 33,an integral pilot extension 35 of the shank 11 being engaged in theinner race of the mentioned taper roller bearing 13. Said pinion 34 isthe fast gear of the first stage reducing gearing 15.

. The output shaft 12, at its upper end, is fitted into the inner raceof a radial bearing 36 mounted in the bore 21 of the body 20. The outerrace of the taper roller bearing 13 is also fitted into said inner race.Thus, the pilot extension 35 of the shank 11 and the upper end of theshaft 12 are retained in alignment by the radial properties of bearing13 and the same are in anti-friction end thrust engagement due to thethrust-taking properties of said bearing 13. A radial bearing 37, partlyin the bore 21 of the body 20 and partly in an aligned bore in thebottom plate 26, is mounted so as to journal the shaft 12 in cooperationwith the bearing 36. Said shaft is provided, in its lower portion with atapered. socket 38 that is adapted to receive the similarly taperedshank of a drilling or similar tool of conventional design. Shaft 12 isshown with a knock-out slot 39 that extends from the upper end of socket38 and in approximate register with the openings 28 in the housing body,as best seen in FIG. 1.

By means of the above arrangement, the shank of a tool, carried by theshaft 12, extends partly into the body, providing for a close-coupledarrangement of tool and attachment that minimizes flexure of the toolduring a drilling or boring operation. It will be clear the openings 28afford access to the slot 39 for a tool-dislodging member.

As can be seen in FIG. 2 a ring or washer 40 is held by the cap plate 24in a hold-down relation to the upper radial bearing 36. In thisconstruction it is preferred that the bearings 33, 36 and 37 be sealedbearings, i.e., those that will not pass lubricant therethrough andwhich retain pre-packed lubricant.

The first stage reducing gear 15 comprises the mentioned pinion 34 onthe shank 11 and a mating gear 41 on the countershaft 14. A pilotextension 42 on the countershaft 12 is held by a needle bearing 43journalled in the cap plate 24. The ratio of the gears 34 and 41 isshown, in this case, at about one to three and one-half.

The second stage reducing gearing 16 comprises a pinion gear 44 integralon the lower end of the countershaft 14, and a ring gear 45 matingtherewith and carried by the shaft 12. The ratio of these gears may bein the nature of one to three or three and one-half, thereby providingan overall reducing ratio of one to ten or twelve, as desired, with acommensurate increase in power; a

pilot extension 46 on the lower end of the countershaft 14 is held by aneedle bearing 47 journalled in the lower portion of the body 20.

The shear means 17 is shown as shear pins 48 connecting the shaft 12 andthe ring gear 45. The same will shear under excessive resistance to thetorque on the shaft by the tool carried by said shaft, thereby savingwear or reakage of the gear teeth of the several gears. Such pins areeasily replaced, since they may be knocked out and replaced withoutdisassembling the tool, because of access thereto through either of the.slots 28.

Since the bore 21 is open due to the slots 28, the various O-rings 18,as shown, are provided to prevent leakage of lubricant that may spillfrom said slots 28.

Since drill presses are but examples of the type of machine on which thepresent attachment may be used, the same should be considered asgeneric.

While the foregoing has illustrated and described what is nowcontemplated to be the best mode of carrying out the invention, theconstruction is, of course, subject to modification without departingfrom the spirit and scope of the invention. Therefore, it is not desiredto restrict the invention to the particular form of constructionillustrated and described, but to cover all modifications that may fallwithin the scope of the appended claims.

Having thus described this invention, what is claimed and desired to besecured by Letters Patent is:

1. A drill press attachment comprising:

(a) a housing adapted to be mounted on the arbor of said press andhaving lateral knock-out openings,

(b) means to hold the housing non-rotational,

(c) axially aligned input and output shafts extending in oppositedirections from said housing with a major portion of the output shaftdisposed within the housing,

(d) a thrust-receiving bearing carried by one of said shafts and inthrust-taking engagement with the other,

(e) reducing gearing in the housing inter-connecting the shafts to driveone shaft slower than the other, and

(f) the slower shaft having a tool-receiving socket and a knock-out slotlongitudinally aligned with the mentioned openings in the housing toprovide access for a member to dislodge a tool fitted into said socket.

2. A drill press attachment according to claim 1 in which an element ofsaid reducing gear is mounted on the slower shaft, and shear meansconnects said element and slower shaft to shear under excessiveresistance to torque of the latter shaft.

3. A drill press attachment according to claim 1 in which seals betweenthe housing and the slower shaft are provided above and below theopenings in the housing to obviate lubricant leakage through saidopenings.

4. A drill press attachment according to claim 1 in which the reducinggearing comprises first and second reducing stages, and a shearconnection between the slower shaft and the second reducing stage toshear under excessive resistance to torque of said latter shaft.

5. A drill press attachment according to claim 1 in which the housingholding means comprises:

(a) a rigid lateral arm on the housing,

(b) a length-adjustable sleeve on said arm, and

('c) means to connect said sleeve to the column of said press.

6. A drill press attachment comprising:

(a) a housing adapted to be mounted on the arbor of said press andhaving lateral knock-out openings,

(b) means to hold the housing non-rotational,

(c) axially aligned input and output shafts extending in oppositedirections from said housing with a major portion of the output shaftdisposed within the housing,

((1) a thrust-receiving bearing carried by one of said shafts and inthrust-taking engagement with the other,

(e) reducing gearing in the housing inter-connecting the shafts to driveone shaft slower than the other,

(f) a radial bearing for the faster shaft,

(g) two longitudinally spaced radial bearings for the slower shaft, and

(h) the slower shaft having a tool-receiving socket and a knock-out slotlongitudinally aligned with the mentioned openings in the housing toprovide access for a member to dislodge a tool fitted into said socket.

References Cited by the Examiner UNITED STATES PATENTS 1,444,343 2/1923Goodwin 74-421 1,674,200 6/1928 Gatten 74421 2,428,049 9/1947 Tate 74421X DON A, WAITE, Primary Examiner.

6. A DRILL PRESS ATTACHMENT COMPRISING: (A) A HOUSING ADAPTED TO BEMOUNTED ON THE ARBOR OF SAID PRESS AND HAVING LATERAL KNOCK-OUTOPENINGS, (B) MEANS TO HOLD THE HOUSING NON-ROTATIONAL, (C) AXIALLYALIGNED INPUT AND OUTPUT SHAFTS EXTENDING IN OPPOSITE DIRECTIONS FROMSAID HOUSING WITH A MAJOR PORTION OF THE OUTPUT SHAFT DISPOSED WITHINTHE HOUSING, (D) A THRUST-RECEIVING BEARING CARRIED BY ONE OF SAIDSHAFTS AND IN THRUST-TAKING ENGAGEMENT WITH THE OTHER, (E) REDUCINGGEARING IN THE HOUSING INTER-CONNECTING THE SHAFTS TO DRIVE ONE SHAFTSLOWER THAN THE OTHER, (F) A RADIAL BEARING FOR THE FASTER SHAFT, (G)TWO LONGITUDINALLY SPACED RADIAL BEARINGS FOR THE SLOWER SHAFT, AND (H)THE SLOWER SHAFT HAVING A TOOL-RECEIVING SOCKET AND A KNOCK-OUT SLOTLONGITUDINALLY ALIGNED WITH THE MENTIONED OPENINGS IN THE HOUSING TOPROVIDE ACCESS FOR A MEMBER TO DISLODGE A TOOL FITTED INTO SAID SOCKET.